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2b6c6b1 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 | import numpy as np
import torch
from PIL import Image
from typing import Tuple, Optional
from musubi_tuner.dataset import image_video_dataset
# prepare image
def preprocess_image(
image: Image, w: int, h: int, handle_alpha: bool = False
) -> Tuple[torch.Tensor, np.ndarray, Optional[np.ndarray]]:
"""
Preprocess the image for the model.
Args:
image (Image): The input image. RGB or RGBA format.
w (int): The target bucket width.
h (int): The target bucket height.
handle_alpha (bool): Whether to handle alpha channel for tensor and numpy array.
Returns:
Tuple[torch.Tensor, np.ndarray, Optional[np.ndarray]]:
- image_tensor: The preprocessed image tensor (NCHW format). -1.0 to 1.0.
- image_np: The original image as a numpy array (HWC format). 0 to 255.
- alpha: The alpha channel of the image if present in original size, otherwise None.
"""
if image.mode == "RGBA":
alpha = image.split()[-1]
else:
alpha = None
if handle_alpha:
image = image.convert("RGBA")
else:
image = image.convert("RGB")
image_np = np.array(image) # PIL to numpy, HWC
image_np = image_video_dataset.resize_image_to_bucket(image_np, (w, h)) # TODO move this to this file
image_tensor = torch.from_numpy(image_np).float() / 127.5 - 1.0 # -1 to 1.0, HWC
image_tensor = image_tensor.permute(2, 0, 1).unsqueeze(0) # HWC -> CHW -> NCHW, N=1
return image_tensor, image_np, alpha
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